Ah, OK, about the same time I had an uncle that gave me a used Hallicrafters S-110 or S-120 5 tube radio with 3 or 4 bands. Then I mowed lawns and pulled weeds to earn enough to afford my first Heathkit 3 tube superregen. In high school a buddy of mine and I bought Realistic DX-150s. We used to listen to hams, mostly 80 meter AM, but didn't know any. I guess my Elmer would be an ex-neighbor of my exwife and his wife. They were both electrical engineering majors and drilled me in the code. I was living near Boston so I drove to the FCC office and did my technician class license. Had maybe 2 cw QSOs and my DX-100 power transformer went up in smoke. About 1977. Lost interest until about 2008 when the FCC had dropped the code requirement. Studied a month and jumped from nothing to Extra class in one evening.
RX with a cereal-box PCB and a shoebox case
That sounds like fun, I never did have a working crystal radio.
I need to find a forum where people talk about the nuts and bolts of SDR. I have some RTL2832 dongles, I started with rtl_tcp then more recently librtlsdr to get an IQ stream. I use fftw (actually fftwf) and sometimes I see peaks for signals
and sometimes not. My next effort will be to write a version (in C) that loops through parameters like RF and IF gain and dumps out tab-delimited files and Gnuplot scripts and generates plots at the different settings. I think I'm probably overloading the dongle by running the gains too high, which makes the signals go away. And in some places I read that dongles with the R820T tuner chip (like mine) don't have an IF gain setting even though librtlsdr lets me set one.
But I've been playing around with plotting methods too
Because the graphics on the screen need to move, which is tricky in X. And I'm keeping an eye on CPU usage. I've been through framebuffer graphics, vnclib virtual framebuffers, now I've come back to just drawing in XLib. Except I want some widgets for buttons, frequency readout, etc, so probably Motif since it's easier than GTK. Except my peaks keep going away. This was just xlib, I think.
So still radio. I've used SDR software like GQRX, hdsdr, sdrsharp, but I wanted to understand better how they actually work.
BTW your name made me look up ka2rrz whose name is also Ron. A transplant from upstate NY to TN. He was just starting to get into Arduinos last I knew about 2014. He's on Yahoo mail which screws up a lot and blocks my Gmail, eventually we gave up. A couple people I knew in high school are in SC.